PAD Mux in u-boot and kernel

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

PAD Mux in u-boot and kernel

Jump to solution
1,181 Views
rans
Senior Contributor I

Hello,

I see there are pad mux in u-boot board file, and also in kernel device tree files.

Both seems to be about the same.

So, Why is it that both are required ? Why can't u-boot pad also keep on when moving to kernel ?

I am afraid that there might be some differences between both.

Is it that CONFIG_PINMUX shall disable the override of mux in kernel ?

Thank you,

Ran

1 Solution
886 Views
igorpadykov
NXP Employee
NXP Employee

Hi Ran

u-boot pad configs can keep on when moving to kernel using dts settings

described in linux/Documentation/devicetree/bindings/pinctrl/fsl,imx-pinctrl.txt:

Bits used for CONFIG:
NO_PAD_CTL(1 << 31): indicate this pin does not need config.

linux-imx.git - i.MX Linux Kernel 

Since uboot and kernel may be used with other os&bootladers, so seems both pad mux 

are used.

Best regards
igor
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

View solution in original post

1 Reply
887 Views
igorpadykov
NXP Employee
NXP Employee

Hi Ran

u-boot pad configs can keep on when moving to kernel using dts settings

described in linux/Documentation/devicetree/bindings/pinctrl/fsl,imx-pinctrl.txt:

Bits used for CONFIG:
NO_PAD_CTL(1 << 31): indicate this pin does not need config.

linux-imx.git - i.MX Linux Kernel 

Since uboot and kernel may be used with other os&bootladers, so seems both pad mux 

are used.

Best regards
igor
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------